public class Circular{
    Circle bottom;
    double height;
    void setBottom(Circle c) {     //设置圆锥的底是一个Circle对象
      bottom=c;
    }
    void setHeight(double h) {
      height = h;
    }
    double getVolme() {
      if(bottom == null)
        return -1;
      else 
        return bottom.getArea()*height/3.0;
    }
    double getBottomRadius (){
      return bottom.getRadius();
    }
    public void setBottomRadius(double r){
      bottom.setRadius(r);
    }
}

